Table of contents
- 0. Review of Algebra4h 16m
- 1. Equations & Inequalities3h 18m
- 2. Graphs of Equations43m
- 3. Functions2h 17m
- 4. Polynomial Functions1h 44m
- 5. Rational Functions1h 23m
- 6. Exponential & Logarithmic Functions2h 28m
- 7. Systems of Equations & Matrices4h 6m
- 8. Conic Sections2h 23m
- 9. Sequences, Series, & Induction1h 19m
- 10. Combinatorics & Probability1h 45m
0. Review of Algebra
Algebraic Expressions
Problem 143
Textbook Question
Evaluate each expression for x = -4 and y = 2. |3x - 2y|
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1
Substitute the given values into the expression: replace \(x\) with \(-4\) and \(y\) with \(2\).
The expression becomes \(|3(-4) - 2(2)|\).
Calculate the multiplication: \(3 \times (-4) = -12\) and \(2 \times 2 = 4\).
Substitute these results back into the expression: \(|-12 - 4|\).
Simplify the expression inside the absolute value: \(-12 - 4\) and then take the absolute value of the result.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Absolute Value
The absolute value of a number is its distance from zero on the number line, regardless of direction. It is denoted by vertical bars, such as |x|, and is always non-negative. For example, |3| = 3 and |-3| = 3. In the context of the expression |3x - 2y|, it indicates that we will take the positive value of the result after substituting x and y.
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Substitution
Substitution is the process of replacing variables in an expression with their corresponding numerical values. In this case, we substitute x = -4 and y = 2 into the expression 3x - 2y. This step is crucial for evaluating the expression accurately and allows us to simplify it to a numerical value.
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Linear Expressions
A linear expression is an algebraic expression in which each term is either a constant or the product of a constant and a single variable raised to the first power. The expression 3x - 2y is linear because it involves the variables x and y to the first degree. Understanding linear expressions is essential for evaluating and manipulating them in algebra.
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